1. Field
The described technology relates generally to an organic light emitting diode (OLED) display. More particularly, it relates to an OLED display using an oxide semiconductor layer.
2. Description of the Related Art
An organic light emitting diode (OLED) display is a self emissive display device that displays images with OLEDs. The OLED display differs from a liquid crystal display (LCD) in that it does not require a separate light source, resulting in relatively small thickness and weight. The OLED display also provides high quality characteristics, e.g., low power consumption, high luminance, and short response time.
Recently, attention has been particularly drawn to an OLED display with oxide thin film transistors. The oxide thin film transistor refers to a thin film transistor using an oxide semiconductor layer. The oxide thin film transistor has relatively high mobility and reliability compared to a thin film transistor using amorphous silicon, and exhibits excellent uniformity and overall performance characteristics compared to a thin film transistor using polysilicon. In addition, the OLED display with such oxide thin film transistors is advantageous in constructing a transparent display device. However, an oxide thin film transistor having an inverted staggered structure cannot apply an accurate voltage due to parasitic capacitance so that a defect may occur due to a kick-back voltage.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.